The enhancement of security at sensitive locations has always been a concern throughout modern history. At the present time, methods of limiting, controlling, and/or monitoring access of vehicles and personnel to buildings and sites typically include fences, access gates, guardhouses, barricades and related obstacles. Commercially available solutions also include sliding gates, drop bars, bollards, anti-ram walls, hydraulic wedges, hydraulic rising beams, retractable bollards, tire shredders, and ditches.
When a situation involves the potential of forced entry or secret unauthorized entry by personnel on foot or inside vehicles, particularly when aggressive unauthorized entry is involved, the typical approach involved armed personnel, impenetrable fences or gates and/or barricades. This approach has proven to be inadequate in many situations such as those involving people and vehicles both of which may be equipped with explosives.
Other drawbacks of the aforementioned means employed to address these situations involve the inability to assess, or the faulty assessments of, the intention underlying an intrusion. By the same token, miscommunications also tend to promote uncertainty. As a result of these problems, personal injury and/or significant damage to vehicles can easily result in unwanted fatalities and costly material loss.
Solutions to many of the security concerns and problems raised above have been disclosed in PCT/US2006/026495, U.S. Pat. No. 7,405,654 and U.S. Pat. No. 7,760,087, the disclosures of which are incorporated herein by reference. Despite their inherent advantages, the systems and methods disclosed in these references are predominantly effective in specific situations and against specified forms of aggressors and attacks, such as for the protection of an embassy or building from an approaching vehicle or individual carrying explosives, where the explosion and damage are generally intended to be inflicted more swiftly and with greater force and immediate impact. By comparison, in large demonstrations or hostile attacks involving many people and which may commence peacefully but develop and escalate gradually, a fluidized bed alone may be an insufficient defensive measure to protect a given area or building and the individuals within. Once the bed is fluidized, individuals outside the effective fluidized area may avoid or circumvent the proscribed and affected area and seek alternate means to breach the perimeter defenses.
Accordingly, there remains a need to maintain or control perceived hostile situations involving less lethal or non-lethal, yet aggressive congregations of individuals. By the same token, once the affirmative lethal intent of a mob is determined, there remains a significant need to delay the actions of its constituents until help arrives or to enable escape of those who are threatened. In view of the foregoing, there is a need to effectively guard against and disperse hostile groupings of individuals and aggressive demonstrators in a non-lethal manner which promotes the dispersion of these individuals prior to the escalation of an event taking place, for example, outside a government building or on the perimeter of a secured or guarded location.
Generally, various types of tear gas have been utilized by governments and policing agencies and organizations to disperse or quell riots and hostile assemblies of individuals. One of the most notable tear gas compounds is 2-chlorobenzalmalononitride (C10H5ClN2) termed “CS.” This compound is most frequently used due to its strong effect and exhibiting the least toxicity in comparison with other similar chemical agents. However, despite its advantages, establishing a uniform, appropriately concentrated delivery of CS gas to a crowd demonstrating in a given area is difficult because CS is a solid at room temperature, not a gas.
In the prior art, a variety of approaches have been used to make the CS solid serviceable as a gas, including, but not limited to, dissolving the CS solid in an organic solvent and delivering the combination as an aerosol; heating the CS solid in a thermal grenade by generating hot gases to evaporate the CS; melting and spraying CS in its liquid form; and other ways known in the art. However, none of these methods have achieved a reliable or consistently controllable concentration when utilized in amidst a crowd.